Vacuum tube circuits



y 1933. H. l. ROMNES 1,917,064

I VACUUM TUBE CIRCUITS Filed March 16, 1931 ARG/NAL I BE) BET-l8 INVENTOR H. l ROMNES Arrows/5v lamp 21, lower armature and contact arm operating winding of relay 12 causing it to operate. The upper armature closes a circuit through filament 6 actuating it and thereby continuing the operation of the tub-e 2.

The lower armature of relay 12 upon operation closes a holding circuit which may be traced from ground through battery 14:, lower be accidently operated and immediately released before the defective tube is replaced,

the action which occurred when the filament burned out is repeated. After replacement of the defective tube, key 17 is operated to restore relay 12 to its unoperated condition and a circuit from ground, battery 25, winding of the circuit through filament 6 is established.

Another scheme for accomplishing the same purpose, but which has application mainly in tubes where there is no necessity for shunting the plate current away from the filament, is shown in connection with tube 4:. In this case a relay 22 is inserted in the plate current supply circuit of the tub-e. This relay is normally energized or operated and upon 'deenergization causes the energization of a slow-acting relay 23.

Upon failure of filament 8 of tube 4, plate current from +B through relay 22 Will cease to flow. Armature 2 1 in falling back closes relay 23, armature 2 l'to ground.

Relay 23 is thereby operated but is slowacting for reasons which will appear later.

. In operating, relay 23 closes the circuit for filament 8 through its upper armature. By the action of its lower armature it closes a holding and an indicating circuit as pointed out in connection with tube 2. These cir cuits, therefore, need not be traced again.

As soon as filament 8 is heated to the proper temperature plate current again flows through relay 22 causing it to operate thereby breaking the circuit which caused relay 23 to operate and close its holding circuit. Re lay 23, however, remains operated over its holding circuit through conductorlfi and key 17, and maintains the circuit of filament S closed. Y

Relay 23 is made slow-acting to avoid the interruption of the operation of tube 4 in the event of a failure of any othertube in the series. For example, in the case of the failure of tube 2 as described above, filament current of all tubes in the series ceases to flow momentarily until the second filament is cut in. During the cessation of filament current flow, plate current would cease to flow through tube 1 and this would cause the release of relay 22 and the substitution of filament 8 for filament 8 in tube 4:. 1

By making relay 23 sl0w-acting its contacts are kept from closing long enough to permit other relays such as 12 to operate and establish filament current fiow again". Relay 23, therefore, does not cause the closure of its contacts, except upon the failure of itsassociated tube 4-.

When defective tube 4 is replaced, key 17 is operated to establish again the current flow through the main filament 8 of the new tube and to open the circuit of the indicating lamp and the holding circuit of relay 23.

Having described the invention in oneof its embodiments it is to be understood that the invention is not to belimited to such an embodiment but only as defined in the ap-. pended claims.

What is claimed is:

1. In combination, a plurality ofspace dis a charge devices each of said devices equipped with a main filament and an auxiliaryfilament, a relay associated with each of said devices having awinding shunted around a portion of the filament current circuitof said devices, and adapted to operate upon change of current flow in said winding, and contacts actuated by the operation of said relay adapted to close the. circuit of said auxiliary fila ment. I v 2. In combination, a plurality of multifilament space discharge devices, a relay con nected in shunt to one filament of each of said devices, circuit control contacts associated with said relay, and means causing said relay to operate upon failure of one of said filaments whereby said circuit control contacts close the circuit for said second filament.

discharge device, a relay having a winding thereof connected in shunt to one of said fila 1nents,said relay being energized by the flow of filament current through its winding when said filament fails and circuit controlling contacts operated-upon the e'nergizationof said.

relay to close the circuit of of said device.

another filament 4. In combination, "a multi-filainent space discharge device, a multi-winding relay as 5. An electrical system containing multi- 3. In combination, a multi-filament space up and inclil'ded, in thel'circpit of a second; fi1 a"- ment, and means to cause the energlzatlorji of "actuated;

njelctrical-lsystem accord ingv t p I11" itngssfwhreof," I hei'lln tds'ilbsribe f I my na me', this; 6th d'ayhf March 1931;.1- HA N- MN s'aid relay upon th-faih ir of the firstfif said 

